1. Field of the Invention
The present invention relates generally to the field of communications, and in particular toward processing encoded messages such as e-mail messages.
2. Description of the State of the Art
In many known message exchange schemes, signatures, encryption, or both are commonly used to ensure the integrity and confidentiality of information being transferred from a sender to a recipient. In an e-mail system for example, the sender of an e-mail message could either sign the message, encrypt the message or both sign and encrypt the message. These actions may be performed using such standards as Secure Multipurpose Internet Mail Extensions (S/MIME), Pretty Good Privacy™ (PGP™), OpenPGP and many other secure e-mail standards.
When an encrypted message is received, it must be decrypted before being displayed or otherwise processed. Decryption is a processor-intensive operation which, on a mobile device with limited processing resources, tends to take a relatively long time, on the order of several seconds. Such time delays may be unacceptable for many mobile device users. Even if the message is not encrypted, it may be encoded in such a way that some processing may be required before displaying the message to the user. Two examples of such encoding would be the Base-64 encoding commonly used to transfer binary data embedded in email messages on the Internet, and the ASN.1 encoding required by many Internet and security standards. The decoding associated with these types of encoding may also cause a time delay that is unacceptable for many mobile device users.
Since the content of encrypted messages should generally remain secure even after receipt, such messages are normally saved to long term storage only in encrypted form and decryption operations must be performed each time an encrypted message is opened. Also, when a user asks to verify a signature on a message, the original message contents are typically required to perform the operation, so messages are often stored in their encoded form. Therefore, each time such an encoded message is opened or displayed for example, the decoding operations must be repeated as well.
There is therefore a general need for a faster and less processor-intensive message processing system and method.